Abstract:Studies show that there is evident correlation between ENOS events and the abnormity of Huaihe river basin’s precipitation. Through power spectrum analysis, there are three obviously common periods, 18 months,26 months and 47 months, about Southern Oscillation and the abnormal sea surface temperature (SST) of the east equatorial Pacific Ocean. However, the abnormality of Huaihe River basin’s precipitation is very complex, there is period of 26 months which is the same period with that of ENSO events. We found the annual distribution law about the abnormity of Huaihe river basin’s precipitation in ENSO events is that:in EL Nino event, the precipitation increases in spring and winter, while in LA Nina event, the precipitation decreases, especially in July. When SOI is on the high side, the Huaihe river basin’s precipitation universally and evidently decreases, especially in September,October and November, the decrement is more than 30%. While SOI on the low side, the Huaihe river basin’s precipitation evidently increases.